4

Get oxygen to blood:
Respiration is the process of bringing oxygen into the lungs and exhaling carbon dioxide out of them. Once inside the lungs, the oxygen crosses cell membranes to get into the blood stream. The blood circulates the oxygen to the rest of the body including the brain which cannot function without it. Carbon dioxide is the waste product of well functioning cells and is also carried back by the blood.
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7

Interesting !?:
Starting from the top: the lips, mouth, throat. trachea, larynx, right and left main stem bronchi, smaller bronchial passages and the tiny alveoli (where oxygen & carbon dioxide are exchanged) and the pulmonary vessels are all part of the respiratory system One of its most remarkable aspects is its ability to make speech and other sounds. There's no other like it in the animal kingdom.
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8

Oxygen and CO2:
Oxygen is needed for your cells to live, and when they burn calories using oxygen they generate co2. Too much co2 is toxic to the brain and it must be removed from the blood. The lungs exhale co2 (like a car's exhaust pipe), and take in oxygen with each breath, lungs transfer oxygen to red blood cells that transport it to your cells.
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9

Upper respiratory:
structures include the sinuses, nasal passages, throat, pharynx, tonsils and vocal cords. Other than allowing passage of Oxygenated air, it is rich in mucus glands to protect the airway from viruses and microbes, It is also rich in immunologic cells to combat microbes.
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10

No:
Exercise, especially aerobic activities, increases & improves both cardiology & pulmonary system, rather than wearing them down. In fact, a recent study concluded that better fitness in middle-age was linked to less lung & colon cancer & cancer death later on (http://oncology.jamanetwork.com/article.aspx?articleid=2203829).
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